The present invention relates to electronic calipers. More particularly, the present invention relates to electronic calipers having multiple function modes, each mode allowing the user to perform a basic mathematical or geometric calculation, such as scaling the measurement by a chosen value, providing a nominal value corresponding to the physical measurement, and/or utilizing physical measurements in geometric formulas to determine other calculable values.
Most calipers currently in use are designed for inspection of existing parts and materials. This is optimal for occupations such as inspector, machinist or fabricator, where the user wants to verify a particular dimension, wants to know a dimension for design of a corresponding part, etc. However, engineers, designers, architects, and pattern makers frequently have different needs. When creating a new part, important information may be obtained for alternate sources, including drawings, catalogues, facsimiles, and photographs. Since, many of these sources are not printed in a known scale and/or rarely have all the necessary dimensions, the user must make repetitive manual calculations using a calculator, a machinists handbook, protractor, an architects scale and a caliper to obtain the desired or necessary values for the new part.
Some prior art device have attempted to overcome some of these limitations. For example, U.S. Pat. No. 4,435,904 to Logan et al. describes an automated measuring scale which aids a user in scaling values by allowing a user to input a scale factor and a scaled number. When the system is then activated, the device automatically moves the index member an amount which is scaled by the scale factor.
U.S. Pat. No. 5,067,249 to Terrigno calculates the number of miles along a path by scaling the distance a rolling disk travels on a map by the corresponding map scale
These prior art devices are limited to a basic scaling of a particular measured distance by an entered scale factor. Therefore, there is a clear need in the industry for a device which is more versatile and allows a user to calculate the scale factor, calculate other values based on measured parameters, display alternate nominal values such as wire or sheet gauge, paper weight, etc. which correspond to a measured value, and measure values which are automatically input into geometric formulas and used to calculate resulting values.
Accordingly, the object of the present invention is to provide an electronic caliper or divider which can convert physical measurements by chosen parameter(s) to calculate and/or display chosen or nominal values while maintaining the ease-of-use, simplicity and elegance of current digital calipers. The present invention is particularly designed to calculate and display scaled values from either an input or a calculated scale factor; display a nominal value corresponding to a measured value such as, wire gauge, sheet metal gauge, paper weight, etc.; a value calculated from a simple geometric function, such as area, radius, angle, perimeter, volume, etc.; or an exact or approximate value calculated from a more complex geometric function, such as moment of inertia, area under a curve, areas of more complex shapes, etc.
In keeping with the forgoing discussion, the present invention takes the form of a set of calipers having a pair of measurement jaws for measuring the distance between points, a display and a calculation module which performs calculations or retrieves values for any one or more of the following functions: scaling, nominal values, basic geometry, and complex geometry.
The scaling function is performed in one of two ways: numerical input or a calculated scaling factor. The numerical input is for cases where the drawings, model, or item to be measured is of a known scale. The user inputs that scale. Further measurements are then multiplied by this scale factor and displayed. The calculated scaling factor is for cases in which the user is uncertain of the scale, but has a reference dimension. In this case, the user measures the reference dimension, then inputs the value corresponding to the actual dimension of the object. The calculation module then calculates the scale factor and scales further measurements by the scale factor.
The nominal values function displays the nominal value which corresponds to the measured value of any preprogrammed group. Common groups would include tables of drill sizes, wire gauge, sheet metal gauge, screw size, font size, paper weight, hole size, etc. Optimally, this function also displays nominal values for manually input values or scaled values.
The basic geometry function calculates geometric values based on one or more measured inputs. For example, the user can measure the opposite and adjacent legs of a triangle and the caliper will calculate and display the angle. Geometry functions can be programmed for radius, angle, area, perimeter, volume, etc. These measurements could be measured in many units, inch, metric, and scaled.
With the complex geometry function, the user can input measured inputs and obtain exact or approximate value for more complicated values such as area, moments of inertia, area under a curve, etc. The caliper may be designed to display in pictorial form different items, like an I-beam. The user can then measure different values as the caliper prompts the user for specific measurements. When all the measured inputs have been entered, the caliper will display the results. Again, many units can be used, inch, metric, or scaled. For embodiments where the user is prompted for information on a pictorial display, a larger display is used to allow for the pictorial image.